Double disk harrow



4 SHEETS'SHEET 1 Jam, 16, 31923.

J C. BOHMKER ET AL. DOUBLE DISK HARROW FILED MAY 5, 1919.

a a 7. 1W 9W? 4 m WW M W: QW M Mb W Jam 16, 1923; 11,442,599

J C. BOHMKER ET AL.

DOUBLE DISK HARROW.

F1 LED MAY 5 1919 4 SHEETS-SHEET 2 Jan. 16, 1923. 1,442,599

J. C. BOHMKER ET AL. DOUBLE DISK HARROW.

FILED MAY 5, 1919. 4 SHEETS-SHEET 3 Jan. 16, 1923. 1,442,599

J. C. BQHMKER ET AL. DOUBLE DISK HARRow.

FILED MAY 5, 191 9, 4 SHEETSSHEET 4 Patented Jan. 16, 1923.

JOHN G. BOHMKER AND JOHN GEISTWHITE, OF KANKAKEE, ILLINOIS, ASSIGNORS TO SEARS, ROEBUCK AND (10., OF CHICAGO, ILLINOIS, A CORPORATION OF NEW YORK.

DOUBLE DISK HARROW.

Application filed May 5, 1919.

To all whom it may concern-.-

Be it known that we, JOHN C. BOHMKER and JOHN GEIST'WHITE, citizens of the United States, residing at Kankakee, in the county of Kankakee and State of Illinois, have invented -certain new and useful Improvements in Double Disk Harrows, of which the following is a specification.

The invention relates to disk harrows of the double or tandem type embodying four gangs of disks arranged in front and rear sections operatively connected together; and the general object of the invention is to provide a harrow of extreme simplicity which at the same time is of a very eflicient and practical character.

A more specific object of the invention is to provide improved connecting means between the disk gangs of the front and rear sections which when the harrow is in use, are capable of maintaining all of the gangs in their proper positions relative to each other and the ground, and which facilitates the turning of the harrow.

In prior barrows of this general type, it has been thought necessary to employ a rigid frame or superstructure to which the disk gangs of the rear section may be pivoted and, in some instances, upon which operat ing levers may be mounted. An important object of our invention is to provide such connections between the forward and rear gang sections and between the two gangs of the rear section, as to render unnecessary the employment of such a superstructure, thus greatly simplifying the construction of the harrow.

The objects of the invention thus generally stated, together with other and ancillary advantages, are attained by the construction and arrangement illustrated in the accompanying drawings forming part hereof, in which Figure 1 is a plan view of a harrow embodying the features of our invent-ion. Fig. 2 is a similar view showing the disk gangs in different relative positions. Fig. 3 is a side elevation of the harrow. Fig. 4 is a fragmental section showing the connection between the two rear disk gangs. Figs. 5. 6 and 7 are detached detail views of certain parts of the harrow. Fig. 8 illustrates the approximate positions assumed by the disk gangs in turning the harrow.

The double disk harrow shown in the accompanying drawings embodies a preferred Serial No. 294,836.

' form of our invention and comprises a draft frame 1 having pivoted thereto two gangs of disks 2 and 2 which constitute the front gang section. 3'and 3 indicate two gangs of disks connected together and constituting the rear gang section of the harrow which is operatively connected with the front section, and a designates two hand le vers mounted on the frame and operatively connected to the gangs 2 and 2 so as to be capable of swingin them to the desired angle relative to eac other, the connections between the two gangs of the two sections being such that when the front gangs are swung in one direction their corresponding rear gangs are swung in opposite directions, as hereinafter set forth.

The draft frame 1 may be of any suitable or preferred construction and may embody rearwardly extending arms 5 upon which the front disk gangs are pivotally mounted. The front gangs are thus permitted to swing relative to the frame when it is desired to vary the angular positions thereof.

The gangs 2 and 2 of the front section and the gangs 3 and 3 of the rear section are of similar construction, each comprising a series of disks 6 mounted upon a rod 7 and. held in spaced relation by means of spacing members 8 in the usual manner. Surrounding the end spacing members 8 of the and also an intermediate member, are be ing members 9, 9 and 9 and rising fr each of these bearing members is a post 10 for supporting a top bar 11 which carries .1. plurahty of disk scraper bars 12.

The bearing members 9 and 9 constitute a part of the means by which the gangs are connected together and to the frame 1 and are preferably made in two sections 13 (Fig. 5) having on opposite sides ears 14 secured together by means of bolts 15. The adj a- 'ent faces of said ears are recessed as at 16, and the recesses of the two sections of the bearing form sockets for receiving the part or parts to which the member is to be pivotally connected by means of the bolts 15, the recesses being shaped so that the sockets permit of a limited swinging movement of the parts mounted therein. In this manner the l bearing members 9 of the forward gangs 2 and 2 are pivotally connected at their forward sides to the rear ends of the arms 5 of the frame; and similarly connected to the members 9 of the forward gangs are the rear ends of a pair of operating bars 17, each pivotally connected at its forward end to the hand lever 4 which is pivoted at 18 on the frame, and guided in its longitudinal movements by a slotted bracket 17. Preferably this bracket has a pair of slots 17" through which the securing bolts are passed thereby permitting the vertical adjustment of the. bracket in case it is desired to vary the depth at which the harrow is to operate. Each of the levers 4 is provided with a locking device 19 adapted to cooperate with a toothed segment 20 fixed on the frame, and it will be seen that by manipulating the lever the forward disk gangs may be readily swung to the desired angle with reference to each other.

The means for connecting the rear disk gangs 3 and 3 to their respective forward gangs are so arranged that when said forward gangs are swung by the operation of the lever 4 the rear gangswill also be swung, but in the opposite direction. Said means are preferably in the form of two diagonally arranged connecting members 22 and 23, the former of which connects the inner bearing member 9 of each rear gang with the relatively stationary bearing member 9 of the gang in front of it, and the latter of which connects the member 9 of each rear gang to the swingable member 9 of the corresponding forward gang. The members 22 and 23 thus cross each other and preferably each comprises a main portion 24 and forward and rear extensions 25 and 26 by which they are connected to the bearing members 9 and 9 through the medium of pivoted parts 27. Said parts 27 are pivotally connected to the bearing members 9 and 9 so as to swing on a vertical axis by means of the bolts 15, and the extensions 25 and 26 are in turn pivotally connected to said parts, so as to swing on a horizontal axis, by pivot pins 28.

It will be seen see Fig. 8 that the members 22 and 23 constitute connections between the gangs of the front and rear sections which are of a character permitting the front and rear sections to move laterally relative to each other when the harrow is being turned. As a result, the turning operation is materially facilitated, and moreover. it is found that the turn may be made on an extremely short radius.

To assist the members 22 and 23 in holding the inner ends of the rear gangs substam tially against movement while the outer ends thereof are being swung, said gangs are connected together by suitable means such, for example. as a chain 29, the opposite ends of which have swivelled connections with the inner ends of the rear gangs. Referring to F ig. 4, such swingable connection for each of the gangs 3 and may comprises a connecuing member 30 mounted at one end on the inner end of the rod 7 and a headed pin 31 pivotally mounted in the opposite end of said member and split to receive the end link of the chain 29 which is held in position by means of a pin 32.

It will be seen that by the construction and arrangement set forth when the hand levers 4 are operated from the position shown-in Fig. 1 to swing the inner ends of the forward disk gangs rearwardly into the position shown in Fig. 2, the connections between the forward gangs and the rear gangs cause the outer ends of the rear gangs to swing rearwardly. Thus both the forward and rear gangs of the harrow may be readily swung to the desired positions relative to each other by simply operating the levers 4, and the gangs on opposite sides of the harrow may be operated independently.

In the use of double disk harrows the inner ends of the forward gangs tend to rise upwardly out of the ground while the outer ends tend to move downwardly. On the other hand, the inner ends of the rear gangs tend to move downwardly and the outer ends upwardly. In order to equalize the forces acting to thus decrease the efficiency of the harrow, we arrange the diagonal connecting members 22 and 23 so that the members 22 which connect the outer portions of the forward gangs to the inner ends of the rear gangs extend across and above the members 23 which connect the inner ends of. the forward gangs to the outer portions of the rear gangs. By this arrangement the tendency of the inner ends of the forward gangs to rise is counteracted by the tendency of the inner end of the rear portion to lower, the portions 24 of the members 22 and 23 interengaging in this. operation. Preferably such portions 24 of the members 22 and 23 are made angular in cross section so as to impart sufiicient rigidity thereto to effectively resist the bending strain to which the members are thus subjected.

The normal tendency of the two forward gangs of the harrow is to move toward each other while the rear gangs tend to separate. The inner ends of the forward gangs are accordingly provided with suitable bumpers 33 and the connection between the rear gangs prevents them from spreading. Thus the forces actin upon the several gangs are effectively equalized, so that any tendency of the gangs of the forward and rear sections to swing laterally relative to each other is effectively overcome. Moreover. by reason of this connection between the rear gangs it will be seen that it becomes unnecessary to employ special end thrust bearings for the gangs as is the case when the gangs are not connected but are pivoted to a superstructure or frame so that their outward movement must be resisted by the bearings carried by such frame. The use of a superstructure is thus dispensed with and at the same time the harrow possesses a high degree of efficiency in operation and the construction is materially simplified so that the cost of manufacture is materially reduced.

For the purpose of holding in position the top bar 11 of each gang, which supports the disk scraper bars 12, suitable braces 34 are provided which extend between the posts 10 and adjacent parts. Herein such parts in the case of the forward disk gangs are the rearwardly extending arms 5 of the draft frame and the operating bars 17, and in the case of the rear disk gangs, such parts are the rearward extensions 26 of the connecting membersl22 and 23.

The braces 34 as thus mounted do not interfere with the swinging movements of the gangs.

As a means for limiting the extent of relative swinging movement of the disk gangs, we preferably provide sectional folding bars 35, the sections 35 and 35 of which are pivotally connected together as at 36 and at their opposite ends to the'outer ends of the angular portions 24 of the diagonally connecting members 22 and 23, as shown at 37 and 38. In order to prevent the sections 35 and 35" from swinging into dead center and thereby preventing the easy flexing of the sections when it is desired to swing the disk gangs into parallel relation, suitable means are provided. Herein a stop lug 39 is formed on the foremost section 35 of the bar which is adapted to engage with the outer edgeof the section 35", to accomplish the desired result. By this construction it Will be seen that when the disk gangs have been swung to their extreme angular positions, as limited by the bars 35, the strain upon the operating levers st and associated parts is relieved. Moreover. any extreme pressure exerted upon the inner ends of the gangs by reason of their becoming clogged with earth and trash, tending to force them to assume greater angles relative to each other, is effectively resisted. It will be apparent that we have provided a disk harrow of a very practical character. By reason of its great simplicity in construction it can be manufactured at a relatively low costand at the same time its efficiency is not diminished but is rather increased. The connecting means between the several disk gangs are adapted to effectively maintain them in their proper positions relative to each other, and in the straightahead travel of the harrow. such means also cause the rear gangs to follow the forward gangs without swinging froniside to side.

Moreover. the peculiar connecting means between the front and rear sections of the harrow lends a sufficient degree of flexibility thereto to enable the rear section in turning to avoid dragging and to swing automatically with reference to the front section so that the planes of rotation of the disks swing toward the direction of travel which the rear disks must take to -"track" the front disks, and in consequence the harrow as a whole may turn on a very short radius.

\Ve claim as our invention l. A disk harrow having. in combination. a draft frame, a pair of forward disk gangs pivotally connected to said frame. a pair of rear disk gangs independent of said frame, a pair of diagonally arranged members pivotally connecting each of said rear gangs to the gang in front of it. means flexibly connecting the two rear gangs together, and means for swinging the forward gangs and thereby the rear gangs but in opposite directions.

A disk harrow having. in combination. a draft frame having two rear 'ai'dly ex tending arms, a pair of forward disk gangs respectiw'ely pivoted to said arms. means for swinging said forward on their pivots, a pair of independent members pivotally connected to the pivoted portions of each of the forward gangs and extending rearwardly therefrom, a rear disk gang pivotally connected to each of said members. and a second pair of members pivot-ally connecting the swinging portions of each of the forward gangs to portions of the rear gangs so as to be swingable with the forward gangs but in opposite directions.

3. A disk harrow having. in combination. a pair of forward disk gangs and a pair of rear disk gangs. each of said gangs having a. pair of spaced bearing members. draft means to which the outermost bearing members of the two front gangs are pivoted. and connecting means between each of the forward gangs and its corresponding rear gang comprising a pair of connecting elements pivoted IGSPGCtlXGlY at their forward ends to the oute' and inner bearings of the front gang and at their r ar ends to the inner and outer bearing members of the rear gang whereby said elements extend transversely of each other and connect the inner bearing member of the rear gang to the outer bearing member of the forward gang. and the outer bearing member of the rear gang to the inner bearing member of the forward gang.

i. A disk harrow having. in combination. a draft frame. two forward disk gangs each having a pair of bearing members one of which is pivotally connected to the frame. two rear disk gangs each having a pair of bearing members and pairs of diagonally arranged independent members pivotally connecting the opposite hearing members of front and rear gangs.

5. A harrow having. in combination. a draft frame. a pair of disk gangs pivotally connected to said frame to swing relative thereto, a second pair of disk gangs operatively connected with the first mentioned gangs so as to swing therewith but in oppo site directions, said connections between the two pairs of gangs being independent of said frame and in the form of two pairs of diagonally arranged members having relatively rigid central portions and bent extensions pivotally connected to the respective gangs.

6. A harrow having, in combination, a draft frame, a pair of disk gangs pivotally connected rearwardly and to opposite sides of said frame, a second pair of disk gangs operatively connected independently of said frame to the first mentioned gangs, means flexibly connecting the last mentioned gangs so as to permit relative bodily movement therebetween, means for swinging the first pair of gangs and thereby the second pair of gangs, and means for limiting the extent of swinging movement of said gangs.

'7. A harrow having, in combination, a draft frame, a forward section comprising two disk gangs pivotally connected to said frame rearwardly thereof, a rear sect-ion comprising two disk gangs operatively connected together and to the gangs of the forward section, connections between the for ward and rear gangs comprising members supported wholly on said gangs connecting the opposite ends of a forward and a rear gang, said members being arranged so as to interengage whereby to counteract the tendency of the inner ends of the forward gangs to rise and the inner ends of the rear gangs to lower, and means for swinging the forward gangs and thereby the rear gangs.

8. A harrow having, in combination, a frame, a disk gang pivoted to the frame, a second disk gang operatively connected to the first mentioned gang, said connection comprising members having their sole support upon and connecting the opposite .ends of said gangs and including central rigid portions adapted to slidably engage with each other whereby to maintain said gangs in parallel relation with the ground.

9. In a double disk harrow, a pair of pivotally mounted disk gangs, a second pair of disk gangs flexibly connected together, and means connecting the second pair of gangs to the first mentioned gangs comprising diagonally arranged members having rigid portions interengaging to maintain the disk gangs parallel to the ground.

10. In a double disk harrow, a pair of pivotally mounted disk gangs. a second pair of gangs having a swivel connection therebetween, and means connecting each of said second pair of gangs to a forward. gang comprising two diagonally arranged members one of which connects the inner end of the rear gang to the pivoted portion of the forward gang and the other of which connects the inner end of the forward gang to the outer end of the rear gang, the last mentioned member being disposed beneath the first mentioned connecting member and adapted to engage therewith whereby the inner end of the forward gang is prevented from rising and the inner end of the rear gang is prevented from lowering.

11. A disk harrow comprising, in combination, a pair of forward disk gangs, a frame to which said gangs are pivotally connected, a pair of rear disk gangs, a pair of connecting bars pivotally connecting each of the rear gangs to its corresponding forward gang adapted to permit of the lateral movement of the rear gang with reference to the forward gang, and a flexible link connecting the rear gangs permitting of relative endwise movement therebetween.

12. A disk harrow having, in combination, a draft frame, a pair of disk gangs pivotally connected to said frame, a second pair of gangs operatively connected together and to the first pair of gangs, said connection between the gangs of the second pair comprising flexible means including a part secured toeach of said gangs, and a member connecting said parts together and having a swivelled connection with at least one of said parts.

13. In a double disk harrow, a pair of pivotally mounted forward disk gangs and a pair of rear disk gangs, means for swinging the forward gangs on their pivots, connecting means between the forward and rear gangs and between the two rear gangs supported wholly by said gangs and adapted to cause the rear gangs to swing with the forward gangs but in opposite directions and permitting the forward and rear gangs to swing laterally relative to each other and the rear gangs to move endwise with respect to each other while the harrow is being turned.

14. A harrow having, in combination, a draft frame, a disk gang pivotallyconnected to said frame and located rearwardly thereof, a second disk gang located rearwardly of the first mentioned gang and operatively connected thereto, said connection comprising members having their sole support upon and connecting the diagonally opposed ends of said gangs and adapted to swing said gangs in variable angular relation to each other, and means to limit the maximum angle between said gangs comprising a pair of pivotally connected elements having pivotal attachment to each of said members and arranged to be swung relatively to each other by said members so that said elements will be in approximate alinement when said members and said gangs are swung to their maximum angles.

15. In a disk harrow, a. disk gang, a second disk gang located rearwardly thereof, a

pair of diagonally arranged elements pivotally connecting said disk gangs whereby said gangs may be moved into angular relation, and means to limit the angular relation between said gangs comprising a flexible member connecting said elements and adapted to be extended to its maximum length when said gangs are moved to their maximum angular relation.

16. A disk harrow having, in combination, a draft frame, a pair of front disk gangs connected to said draft frame, a pair of rear disk gangs having their adjacent ends flexibly connected, and a pair of diagonally arranged elements disposed between one each. of said front. gangs and one each of said rear gangs, said elements having spaced pivotal connections with said front and rear gangs, whereby upon turning said harrow said rear gangs automatically swing into angular rela tion to said front gangs and thereby swing the planes of rotation of the rear disks toward their lines of travel.

17. In a harrow, in combination, a front disk gang, draft means connected to said front gang, a rear disk gang, and means comprising a plurality of pivotally mounted independent members connecting said front and rear gangs whereby upon turning said harrow said rear gang automatically swings into angular relation to said front gang and thereby effects the swinging of the planes of rotation of said rear disks toward their lines of travel.

18. In a double disk harrow, the combination of a pair of forward disk gangs and a pair of rear disk gangs, means connecting the rear gangs to the forward gangs adapted to permit of their relativelateral swingingmove ment, means acting to limit the movement of separation between the outer ends of each of the rear gangs with respect to the outer ends of their corresponding forward gangs, and means connecting the two rear gangs whereby the connecting means between the front and rear gangs on one side of the harrow is adapted to limit the movement of sep aration between the inner ends of the gangs upon the opposite sides of the harrow.

In testimony whereof we have hereunto set our hands.

JOHN C. BOHMKER. JOHN GEISTWHITE. 

